325i (N53B30) misfire help

e92_josh · 02-20-2021, 01:04 PM

Hey, got some trouble I need some advice on...

Car: 2008 E92 325i (N53B30)

Here's the story so far,

- Car developed a misfire during a drive, after the engine came up to temp. The EML triggered and 29D1 was stored. This is cylinder 5 misfire.
- I ordered a set of new spark plugs as I intended on swapping these first before anything else. The car had a full set of new Bosch Coil Packs installed at the end of last year.
- I had the engine cover off yesterday and discovered the following things

1. Coil pack 5 was loose on top of the spark plug. This has caused lots of black 'soot' inside the coil pack and on top of the spark plug. It looks a mess.
2. After removing the spark plugs, they appeared to be the wrong part. I bought NGK - ZKBR7A-HTU 91785. The plugs i removed were Bosch - ZGR6STE2. These are longer and have a wider electrode than the NGK.
3. The small fuel rail leading to the cylinder 5 injector is leaking, fuel visibly pooling on top of the injector from the 14mm nut, and presumably leaking into the spark plug hole.

I installed the new NGK parts and refitted the coil packs. The misfire is worse than before now

with a new code being triggered 2E1C (ignition cylinder 5).

Any advice on NGK vs the Bosch plugs?

I believe the presumably faulty coil pack on cylinder 5 is down to the leaking fuel rail. The leak was probably caused by my local indy as they fitted a valve cover gasket at the start of January. I can't see how the valve cover can come off without removing the small rails??

Tomorrow i'm going to swap cylinder 5 coil pack with cylinder 1 and see if the misfire follows.
The indy garage is expecting the car Monday to fix the fuel rail leak (I tried tightening the 14mm but it won't budge), but right now it needs to be towed.

They also said it'd be safe to drive as long as I wrapped a cloth around the fuel rail... Not sure about that haha!

I also have classic leaking injector symptoms and it appears to be in cylinder 6 (judging by the state of the old spark plug).
I checked the indexes of the injectors that are in there now:

Cylinder 1. Index 09
Cylinder 2. Index 02
Cylinder 3. Index 07
Cylinder 4. Index 11
Cylinder 5. Index 02
Cylinder 6. Index 08

Am I right in thinking that Index 11 should only be banked with other index 11 injectors? So really, cylinder 5 & 6 should be swapped to index 11?

Sorry for the motherload here, it never rains it pours I guess. I've also developed an ABS sensor failure in last couple of days too but i'll not get into that now!!

Phil325i · 02-21-2021, 03:19 AM

I'd always trust NGK (assuming they're not counterfeit of course). And yes, BMW say you should not mix pre- and post-index 11 in the same bank. Though some people dispute this. And you're right, you have to remove the fuel lines to change the VGC.

Hope you get it sorted.

Dormermike · 02-21-2021, 08:09 AM

Dont use Bosch - use ONLY NGK. Why? Compare side by side and you'll see the bosch are slightly longer!

edit just actually read your post where you say the same thing lol

Check everything is clean too.

e92_josh · 02-21-2021, 11:18 AM

Cheers for the replies, I'll keep the NGK plugs in and give everything a good clean if I can.

I moved the coil from cylinder 5 and thankfully the misfire also followed. So a new ignition coil may at least get me to the garage for the fuel rail repair.

Although I've had the car in this state for 2 years (Bosch plugs and mismatched injector indexes), I wouldn't say it's ever run right haha!

02-20-2021, 01:04 PM	#1
e92_josh Enlisted Member 6 Rep 46 Posts Drives: e92 325i M Sport Join Date: Jan 2019 Location: UK iTrader: (0)	325i (N53B30) misfire help Hey, got some trouble I need some advice on... Car: 2008 E92 325i (N53B30) Here's the story so far, - Car developed a misfire during a drive, after the engine came up to temp. The EML triggered and 29D1 was stored. This is cylinder 5 misfire. - I ordered a set of new spark plugs as I intended on swapping these first before anything else. The car had a full set of new Bosch Coil Packs installed at the end of last year. - I had the engine cover off yesterday and discovered the following things 1. Coil pack 5 was loose on top of the spark plug. This has caused lots of black 'soot' inside the coil pack and on top of the spark plug. It looks a mess. 2. After removing the spark plugs, they appeared to be the wrong part. I bought NGK - ZKBR7A-HTU 91785. The plugs i removed were Bosch - ZGR6STE2. These are longer and have a wider electrode than the NGK. 3. The small fuel rail leading to the cylinder 5 injector is leaking, fuel visibly pooling on top of the injector from the 14mm nut, and presumably leaking into the spark plug hole. I installed the new NGK parts and refitted the coil packs. The misfire is worse than before now with a new code being triggered 2E1C (ignition cylinder 5). Any advice on NGK vs the Bosch plugs? I believe the presumably faulty coil pack on cylinder 5 is down to the leaking fuel rail. The leak was probably caused by my local indy as they fitted a valve cover gasket at the start of January. I can't see how the valve cover can come off without removing the small rails?? Tomorrow i'm going to swap cylinder 5 coil pack with cylinder 1 and see if the misfire follows. The indy garage is expecting the car Monday to fix the fuel rail leak (I tried tightening the 14mm but it won't budge), but right now it needs to be towed. They also said it'd be safe to drive as long as I wrapped a cloth around the fuel rail... Not sure about that haha! I also have classic leaking injector symptoms and it appears to be in cylinder 6 (judging by the state of the old spark plug). I checked the indexes of the injectors that are in there now: Cylinder 1. Index 09 Cylinder 2. Index 02 Cylinder 3. Index 07 Cylinder 4. Index 11 Cylinder 5. Index 02 Cylinder 6. Index 08 Am I right in thinking that Index 11 should only be banked with other index 11 injectors? So really, cylinder 5 & 6 should be swapped to index 11? Sorry for the motherload here, it never rains it pours I guess. I've also developed an ABS sensor failure in last couple of days too but i'll not get into that now!!
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02-21-2021, 03:19 AM	#2
Phil325i Brigadier General 616 Rep 3,194 Posts Drives: E92 325i MSport Coupe Join Date: Apr 2012 Location: UK South East iTrader: (1) Garage List 2009 BMW 325i Coupe [6.00]	I'd always trust NGK (assuming they're not counterfeit of course). And yes, BMW say you should not mix pre- and post-index 11 in the same bank. Though some people dispute this. And you're right, you have to remove the fuel lines to change the VGC. Hope you get it sorted. __________________ E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; 3 x chassis braces; diff brace; N53 V-brace; 034 subframe inserts; BMS clutch stop; BMS CDV; RE g/box mounts; Delrin shift bushes; Saikoumichi OCC; Cyba scoops; BMW Perf Exhaust; HEL s/steel brake hoses; M3 rear spoiler; Recaro Sportster CSs; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof/clear front
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02-21-2021, 08:09 AM	#3
Dormermike Captain 102 Rep 681 Posts Drives: Bmw f10 Join Date: Dec 2015 Location: Uk iTrader: (0)	Dont use Bosch - use ONLY NGK. Why? Compare side by side and you'll see the bosch are slightly longer! edit just actually read your post where you say the same thing lol Check everything is clean too.
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02-21-2021, 11:18 AM	#4
e92_josh Enlisted Member 6 Rep 46 Posts Drives: e92 325i M Sport Join Date: Jan 2019 Location: UK iTrader: (0)	Cheers for the replies, I'll keep the NGK plugs in and give everything a good clean if I can. I moved the coil from cylinder 5 and thankfully the misfire also followed. So a new ignition coil may at least get me to the garage for the fuel rail repair. Although I've had the car in this state for 2 years (Bosch plugs and mismatched injector indexes), I wouldn't say it's ever run right haha!
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